In various commercial, institutional, or residential construction projects, it is common practice to provide a gravel fill below a poured concrete foundation wall, or to provide gravel simply for ground cover in selected locations. Most commonly, sites are relatively clear, and the conveyance and spread of gravel is simply accomplished via front end loader, "Bobcat" brand type loader, or other bladed machine. However, from time to time the need arises to place gravel in locations which are not easily reached by such machines from a convenient dump or staging location where gravel may be stored. Therefore, it would be desirable to provide a means for transport of gravel from such staging area to the desired placement location.
I am aware of various attempts in which an effort has been made to provide a mobile device for pneumatic transport of granular material. Most recently, U.S. Pat. No. 5,147,156, issued Sep. 15, 1992 to Guettler et al. for GOLF COURSE CONSTRUCTION AND MAINTENANCE METHODS reveals the combination of an air compressor, conveyer belt, and a pneumatic pumping device for transporting sand or gravel through a flexible tube to a golf course being constructed or maintained. However, as taught, that device requires the transport to the staging area of a collection of components, and site assembly of the components into a working system. Earlier, U.S. Pat. No. 3,326,608, issued Jun. 20, 1967 to Layne et al. for a MOBILE GRAVELING APPARATUS AND METHOD, teaches how to assemble a trailer with a hopper and pipe necessary for gravel packing a well at a remote location. Still, the trailer does not include a compressed air supply, and the disclosed particulate entrainment device is rather primitive. Finally, U.S. Pat. No. 1,670,133, issued May 15, 1928, shows a truck mounted hopper with bottom discharge which has a gate opening over a mechanical conveyer configured for urging particulates toward an opening into a pneumatic conveying apparatus. As disclosed, the device is without sufficient detail to provide a highly reliable particulate entrainment system in gravel type applications which are of most interest to me.
Therefore, it can be seen that it would be desirable to provide a self-supporting vehicle mounted pneumatic gravel conveyance system, which combines the supply of motive air with a reliable material delivery and entrainment system.